9KLM: Reaction center protein L chain
Cryo-EM structure of the monomeric Rhodobacter sphaeroides G1C LH1-RC core complex. Determined by electron microscopy at 2.6 Å resolution. Released 19 Nov 2025.
- Method
- Electron microscopy
- Resolution
- 2.6 Å
- Organism
- Cereibacter sphaeroides
- Chains
- 33
- Atoms
- 23,521
- Mol. weight
- 356.89 kDa
- Ligands
- BPH, BCL, A1EF2, CDL
- Released
- 19 Nov 2025
Explore 9KLM in 3D
Show helices and sheets
RCSB PDB
PDBe
Secondary structure: helices and β-sheets
9KLM contains 117 α-helices and 35 β-strands across 33 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.
Chains a, b, c, d, e, f, g, i, j, k, n, o, p and q: 1 helix, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 14-45 | 32 | |
Chain A: 3 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 4-9 | 6 | |
| α-helix | 13-37 | 25 | |
| α-helix | 39-41 | 3 | |
Chains B, C, F, G and K: 3 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 4-9 | 6 | |
| α-helix | 13-37 | 25 | |
| α-helix | 43-50 | 8 | |
Chains D and P: 4 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 4-9 | 6 | |
| α-helix | 13-37 | 25 | |
| α-helix | 39-41 | 3 | |
| α-helix | 43-51 | 9 | |
Chains E, I and O: 3 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 4-9 | 6 | |
| α-helix | 13-37 | 25 | |
| α-helix | 43-51 | 9 | |
Chain H: 12 helices, 18 β-strands
| Element | Residues | Length | Sheet |
|---|
| β-strand | 7 | 1 | 10 |
| β-strand | 10 | 1 | 10 |
| α-helix | 12-34 | 23 | |
| β-strand | 43 | 1 | 11 |
| β-strand | 49 | 1 | 11 |
| α-helix | 50 | 1 | |
| α-helix | 57-61 | 5 | |
| β-strand | 62-65 | 4 | 12 |
| α-helix | 66 | 1 | |
| β-strand | 72-75 | 4 | 12 |
| β-strand | 87-89 | 3 | 13 |
| α-helix | 97 | 1 | |
| β-strand | 98-100 | 3 | 13 |
| α-helix | 104-107 | 4 | |
| α-helix | 110-112 | 3 | |
| β-strand | 123 | 1 | 14 |
| β-strand | 129 | 1 | 14 |
| β-strand | 131-133 | 3 | 15 |
| β-strand | 141-145 | 5 | 5 |
| β-strand | 152-154 | 3 | 15 |
| β-strand | 160-170 | 11 | 15 |
| β-strand | 175-182 | 8 | 15 |
| β-strand | 188-192 | 5 | 15 |
| α-helix | 193-195 | 3 | |
| β-strand | 197-198 | 2 | 15 |
| β-strand | 203-204 | 2 | 15 |
| α-helix | 210-212 | 3 | |
| α-helix | 217-219 | 3 | |
| α-helix | 227-243 | 17 | |
| α-helix | 245-247 | 3 | |
Chain J: 4 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 4-6 | 3 | |
| α-helix | 7-10 | 4 | |
| α-helix | 13-37 | 25 | |
| α-helix | 43-50 | 8 | |
Chain L: 19 helices, 7 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 7-9 | 3 | |
| β-strand | 24-26 | 3 | 1 |
| β-strand | 29-31 | 3 | 1 |
| α-helix | 33-56 | 24 | |
| β-strand | 65-66 | 2 | 2 |
| α-helix | 67-70 | 4 | |
| α-helix | 71-73 | 3 | |
| α-helix | 80-84 | 5 | |
| α-helix | 85-111 | 27 | |
| α-helix | 116-129 | 14 | |
| α-helix | 130-134 | 5 | |
| α-helix | 135-139 | 5 | |
| α-helix | 142-144 | 3 | |
| α-helix | 146-147 | 2 | |
| β-strand | 148-149 | 2 | 2 |
| α-helix | 152-162 | 11 | |
| α-helix | 167-169 | 3 | |
| α-helix | 171-198 | 28 | |
| α-helix | 204-208 | 5 | |
| α-helix | 209-220 | 12 | |
| β-strand | 222 | 1 | 3 |
| α-helix | 226-250 | 25 | |
| β-strand | 251 | 1 | 4 |
| β-strand | 255 | 1 | 4 |
| α-helix | 259-263 | 5 | |
| α-helix | 264-267 | 4 | |
5 more chain groups are not listed. Open the entry in the viewer and use the sequence panel to see them.
Molecules and chains
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|
| Reaction center protein L chain | L | protein | 282 | Cereibacter sphaeroides | P0C0Y8 (AlphaFold model) |
| Reaction center protein M chain | M | protein | 308 | Cereibacter sphaeroides | P0C0Y9 (AlphaFold model) |
| Reaction center protein H chain | H | protein | 260 | Cereibacter sphaeroides | P0C0Y7 (AlphaFold model) |
| Light-harvesting protein B-875 alpha chain | A, B, C, D, E, F, G, I, J, K, N, O, P, Q | protein | 54 | Cereibacter sphaeroides | P0C0X9 (AlphaFold model) |
| Antenna pigment protein beta chain | a, b, c, d, e, f, g, i, j, k, n, o, p, q | protein | 49 | Cereibacter sphaeroides | P0C0Y1 |
| protein-U | U | protein | 53 | Cereibacter sphaeroides | U5NME9 |
| Intrinsic membrane protein PufX | X | protein | 82 | Cereibacter sphaeroides | Q7B2Z6 |
Sequence of entity 1 (L), FASTA
>9KLM_1 Reaction center protein L chain (chains L)
MALLSFEQKYRVPGGTLVGGNLFDFWVGPFYVGFFGVATFFFAALGIILIAWSAVLQGTW
NPQLISVYPPALEYGLGGAPLAKGGLWQIITICATGAFVSWALREVEICRKLGIGYHIPF
AFAFAILAYLTLVLFRPVMMGAWGYAFPYGIWTHLDWVSNTGYTYGNFHYNPAHMIAISF
FFTNALALALHGALVLSAANPEKGKEMRTPDHEDTFFRDLVGYSIGTLGIHRLGLLLSLS
AVFFSALCMIITGTIWFDQWVDWWQWWVKLPWWANIPGGING
Sequence of entity 2 (M), FASTA
>9KLM_2 Reaction center protein M chain (chains M)
MAEYQNIFSQVQVRGPADLGMTEDVNLANRSGVGPFSTLLGWFGNAQLGPIYLGSLGVLS
LFSGLMWFFTIGIWFWYQAGWNPAVFLRDLFFFSLEPPAPEYGLSFAAPLKEGGLWLIAS
FFMFVAVWSWWGRTYLRAQALGMGKHTAWAFLSAIWLWMVLGFIRPILMGSWSEAVPYGI
FSHLDWTNNFSLVHGNLFYNPFHGLSIAFLYGSALLFAMHGATILAVSRFGGERELEQIA
DRGTAAERAALFWRWTMGFNATMEGIHRWAIWMAVLVTLTGGIGILLSGTVVDNWYVWGQ
NHGMAPLN
Sequence of entity 3 (H), FASTA
>9KLM_3 Reaction center protein H chain (chains H)
MVGVTAFGNFDLASLAIYSFWIFLAGLIYYLQTENMREGYPLENEDGTPAANQGPFPLPK
PKTFILPHGRGTLTVPGPESEDRPIALARTAVSEGFPHAPTGDPMKDGVGPASWVARRDL
PELDGHGHNKIKPMKAAAGFHVSAGKNPIGLPVRGCDLEIAGKVVDIWVDIPEQMARFLE
VELKDGSTRLLPMQMVKVQSNRVHVNALSSDLFAGIPTIKSPTEVTLLEEDKICGYVAGG
LMYAAPKRKSVVAAMLAEYA
Sequence of entity 4 (A, B, C, D, E, F, G, I, J, K, N, O, P, Q), FASTA
>9KLM_4 Light-harvesting protein B-875 alpha chain (chains A, B, C, D, E, F, G, I, J, K, N, O, P, Q)
MSKFYKIWMIFDPRRVFVAQGVFLFLLAVMIHLILLSTPSYNWLEISAAKYNRV
Sequence of entity 5 (a, b, c, d, e, f, g, i, j, k, n, o, p, q), FASTA
>9KLM_5 Antenna pigment protein beta chain (chains a, b, c, d, e, f, g, i, j, k, n, o, p, q)
MADKSDLGYTGLTDEQAQELHSVYMSGLWLFSAVAIVAHLAVYIWRPWF
Sequence of entity 6 (U), FASTA
>9KLM_6 protein-U (chains U)
MPEVSEFAFRLMMAAVIFVGVGIMFAFAGGHWFVGLVVGGLVAAFFAATPNSN
Sequence of entity 7 (X), FASTA
>9KLM_7 Intrinsic membrane protein PufX (chains X)
MADKTIFNDHLNTNPKTNLRLWVAFQMMKGAGWAGGVFFGTLLLIGFFRVVGRMLPIQEN
QAPAPNITGALETGIELIKHLV
Ligands and cofactors
| ID | Name | Formula | Copies |
|---|
| BPH | Bacteriopheophytin a | C55 H76 N4 O6 | 2 |
| BCL | Bacteriochlorophyll a | C55 H74 Mg N4 O6 | 32 |
| A1EF2 | (6~{E},8~{E},10~{E},12~{E},14~{E},16~{E},18~{E},20~{E},22~{E},26~{E})-2,6,10,14… | C40 H58 | 27 |
| CDL | Cardiolipin | C81 H156 O17 P2 | 4 |
| FE | FE (III) ion | Fe | 1 |
| LMT | Dodecyl-beta-D-maltoside | C24 H46 O11 | 25 |
| LDA | Lauryl dimethylamine-N-oxide | C14 H31 N O | 10 |
| PGV | (1R)-2-{[{[(2S)-2,3-dihydroxypropyl]oxy}(hydroxy)phosphoryl]oxy}-1-[(palmitoylo… | C40 H77 O10 P | 13 |
| U10 | Ubiquinone-10 | C59 H90 O4 | 3 |
Primary citation
Molecular and structural insights into neurosporene accumulation in Rhodobacter sphaeroides G1C. Wu, Y.L., Wang, G.L., Wang, X.P. et al. Photosynth Res (2025) 163:53-53. DOI 10.1007/s11120-025-01174-1 · PubMed
Other PDB entries of the same protein (UniProt P0C0Y8 (AlphaFold model), which also has an AlphaFold model), best resolution first:
- 7P0Q 1.73 Å, F(M197)H mutant structure of Photosynthetic Reaction Center From Rhodobacter Sphaeroides…
- 1RZH 1.8 Å, Photosynthetic reaction center double mutant from rhodobacter sphaeroides with asp L213…
- 2J8C 1.87 Å, X-ray high resolution structure of the photosynthetic reaction center from Rb.…
- 3I4D 2.01 Å, Photosynthetic reaction center from rhodobacter sphaeroides 2.4.1
- 2UWU 2.04 Å, X-ray high resolution structure of the photosynthetic reaction center from Rb.…
- 2UWW 2.05 Å, X-ray high resolution structure of the photosynthetic reaction center from Rb.…
- 2J8D 2.07 Å, X-ray high resolution structure of the photosynthetic reaction center from Rb.…
- 1QOV 2.1 Å, Photosynthetic reaction center mutant with ala M260 replaced with trp (chain M, A260W)
- 1RY5 2.1 Å, Photosynthetic reaction center mutant from rhodobacter sphaeroides with asp L213…
- 6Z02 2.1 Å, Photosynthetic Reaction Center From Rhodobacter Sphaeroides strain RV in surfo…
- 6Z1J 2.1 Å, Photosynthetic Reaction Center From Rhodobacter Sphaeroides strain RV LSP…
- 6Z27 2.1 Å, Photosynthetic Reaction Center From Rhodobacter Sphaeroides strain RV LCP crystallization
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